The prior art has long recognized the demand for decaffeinated beverages such as coffee and tea. Primarily, however, the previously utilized decaffeination techniques have involved the use of organic solvents such as trichloroethylene or chloroform to treat either the vegetable material itself or an aqueous extract thereof, with subsequent separation of caffeine-laden organic solvent, so as to allow further processing of the beverage.
Recently it has been found that certain fatty materials are suitable for decaffeinating vegetable materials and aqueous extracts thereof. These decaffeination techniques are fully described in British patent specification No. 1516208. For economic reasons, it is desirable to recycle the caffeine-laden fatty material, and techniques available for removing the caffeine therefrom prior to reuse include washing with water (British patent specification No. 1516208) and vaporisation (British patent specification No. 1532547).